That is very cheap and its a great game to introduce yourself to the world of pc shooters. It lays out all the objectives really well, and you never find yourself not knowing what to do. Download the demo version off of steam to see if you like it, its free.
They will release an updated model of the wii with a hard drive in a year or so's time. I would put money on it, as the wii seems a lot cheaper than other consoles users wouldn't kick up too much of a stink.
I made the comment as both a PC and 360 live fan but in my experience PC gaming in the UK at least seems a lot more civilised and fun. As with all things it depends on what servers you play on, what games you play, but in my experience CS:Source and team fortress 2 on the pc your a lot less likely to come across people who are just online to berate you. This isn't any sort of system bias or anything, just what I have experienced.
Its because your playing a 360. If you played PC games you wouldn't have these problems. Its also the fact that Halo 3 is notoriously bad for attacting those sorts of players, try Call of Duty 4 or something like Flatout. Or better yet just play private games with your friends.